Electrical switch gear



July 10, 1934. J. H. POWERS ELECTRICAL SWITCH GEAR Filed Aug. 21, 192979 Inventor James f-LPowers,

HLS Attobne designs are well known Patented July 10, 1934 ELECTRICALSWITCH GEAR James H. Powers, Yeadon, Pa., assignor to General ElectricCompany, a corporation of New York Application August 21, 1929, SerialNo. 387,522 9 Claims. (Cl. 175298) My invention'relates to electricalswitchgear, and more particularly to a housing and mounting structure ofthe cubicle type for circuit breakers and accessory apparatus, whereinthe circuit breaker remains stationary during the disconnecting andisolating operations thereof.

In switchgear of the type comprising a circuit breaker of appreciableinterrupting capacity, as of the oil-break type, for example, andaccessory equipment such as panels, disconnecting switches, current andpotentialtransformers, bus bars, etc., arranged within a compartment orcell, it has generally been the prior practice to employ one of twotypes of design, depending on the particular requirements of theinstallation. These in the art and comprise the truck-typepanelequipment and the metalclad type.

In the truck-type of equipment, the oil circuit breaker is mounted upona specially built truck and is adapted to be moved or rolled into or outof the compartment or cell under predeter mined conditions. The movablecontacts of the disconnecting device for the circuit breaker generallyare laterally mounted upon the breaker,

the stationary contacts being at the rear of the,

compartment, that bodily movement of the breaker itself is required toeffect operation of the disconnects. Moreover,the instrument panel,which is likewise mounted upon and carried by the truck may be inspectedat the rear thereof only by withdrawing the truck, including, of course,the circuit breaker, from the compartment, thereby requiring completeinterruption of service with regard to that particular 'circuit breaker.Even if a spare truck is available so that service may be continuedduring inspection of the first-named truck-panel, temporary interruptionof service cannot well be avoided. The arrangement above described mustof necessity be quite massive and occupy considerable space due tohorizontal movement of the truck in opening the disconnects.

The metal-clad type of equipment on the other hand is mounted within thecompartment, or frame thereof, the upper part of which contains thestationary equipment, as bus bars, disconnecting switches, etc. In thistype of design,

the movable disconnecting contacts of the circuit breaker are likewisemounted upon the breaker,

. the coacting stationary contacts being disposed above the breaker, sothat instead of horizontal movement, as in the case of the truck-typedesign, the breaker moves vertically to connect and disconnect theaforesaid contacts. This bodily vertical movement of the comparativelymassive circuit breaker is effected by more or less elaborate hoistingmechanism, depending on the weight of the circuit breaker. Theinstrument panel for this type of design is generally mounted in frontof the circuit breaker and spaced therefrom so that removal of thebreaker may be accomplished without disturbing the panel. This featurenecessitates generous floor space due to the fact that the circuitbreaker is first moved outwardly towards the panel, and then in adirection at right angles thereto in order to clear the panel. In boththe truck and metal-clad types, the movement of the circuit breakergenerally effects an isolating operation, by' means of movable shuttersor the like.

Accordingly, it will be noted with regard to the above discussed designsthat in each case bodily movement of the circuit breaker itself isnecessary in order to effect the disconnecting operation and finalelectrical isolation of the breaker with respect to the equipmentassociated therewith.

A principal object of my invention is the provision of switchgearcomprising a cubicle within which a circuit breaker is mounted, whereinthe circuit breaker may be disconnected and electrically isolated fromits accessory equipment by an individual operation distinct from andindependent of movement of the circuit breaker with respect to thecubicle.

A further object is the provision of switchgear oi the character abovedescribed arranged within a compartment or cell, wherein the operationeffecting disconnection and isolation of the circuit breaker isperformed exteriorily of the circuit breaker compartment withoutnecessitating change in the position of said breaker.

A further object is the isolation of the circuit breaker itself withrespect to the front portion of the compartment whereby the outer doorof the compartment may be utilized as aninstrument panel, inspection ofwhich may be had without interrupting the service of the circuitbreaker.

A further object is the provision of a mounting structure for thecircuit breaker wherein a single truck unit, orequivalent, may be usedfor moving a plurality of breakers into or from their respectivecompartments; and more particularly, wherein the circuit breaker restsupon a station- 105 ary structure spaced .a predetermined distance fromthe floor of the compartment A further object'is the provision ofapparatus of the character above described which shall occupy acomparatively small amount of floor space 110 with the passage 50. atthe rear of the cubicle.

and be less massive than similar apparatus heretofore used.

Other objects and advantages will appear from the following descriptiontaken in connection with the accompanying drawing.

Referring to the drawing, Fig. 1 is an elevational cross-sectional viewof switchgear embodying my invention; Fig. 2 is an elevational frontview of the structure illustrated in Fig. l, partly in section; Fig. 3is a detailed view of structure illustrated in Fig. 1 in anotherposition; a d Fig. 4 is a diagrammatic illustration of circuiconnections.

In Fig. 1 there is shown switch housing and mounting structure of thecubicle type comprising a cell-like structure. The rear wall of thehousing comprises removable sections, 1 and 2, and a fixed section 3.Spaced from section 3 is another removable section, 4, forming, togetherwith an associated section, 5, a conduit compartment or passage;5a, atthe rear of the housing. The top section, 6, and a front section, '7,forming a super structure, are likewise removable for the purpose ofpermitting access to the interior, as will be hereinafter described. Thelower front section comprises a hinged door or panel, 8, upon which maybe mounted instruments and meters as in the case of the usual instrumentpanel. For the purpose of simplicity of the drawing, no instruments areshown mounted upon the door panel 8, it of course being understood thatthe instruments may be readily mounted upon the outer face of the panelin the usual manner, the wiring, etc., being disposed along the innerside thereof.

The housing structure, or cubicle, as it will be hereinafter referredto, is divided by partitions or barriers 9, 10 and 11 into compartments,the

lower compartment comprising the circuit breaker compartment withinwhich is disposed an oil circuit breaker 12, supported upon a tray 13,having side supports 13a, as channel members, resting upon the floor ofthe compartment. The circuit breaker 12 may be of conventional designwith the exception of its disconnecting switching structure hereinafterdescribed, and is provided with the usual breathing pipe 14communicating An emergency vent 16 likewise communicates with thepassage 5a which may exhaust in any suitable manner through the lowerpart or floor of the cubicle. A- member 18 secured to tray 13 hasmounted thereon an upright member 19 to which is secured a yoke-likemember 20 for supporting the circuit breaker. With the circuit breakerunit in the position shown, a combined mechanism bracket and steelprotective diaphragm 21 which is secured to upright 19 forms a frontwall of the circuit breaker compartment. Diaphragm 21 is thereforenormally spaced an appreciable distance from panel 8 forming therewithan operating compartment. Upon the outer face of diaphragm 21 and withinthe operating compartment is mounted the usual operating mechanism 22for the circuit breaker, operative connection therewith being hadthrough an aperture 23 in the protective diaphragm. Mounted upon the topof circuit breaker 12 are stationary contact studs 24 and 25 comprisingthe stationary contact members of the disconnecting devices for thecircuit breaker. As illustrated in Fig. 1, contacts 24 and 25 areengaged by their cooperating movable contacts 26 and 27, whose operationwill be presently described.

The partition 11 forming the top of the circuit operating mechanism.

breaker compartment comprises a compound barrier of. suitable insulatingmaterial-and is provided with apertures 28 and 29 disposed in alignmentwith the longitudinal axes of the movable contacts 27 and 26,respectively. A movable shutter or isolating member 30 of suitableinsulating material is mounted for reciprocal movement with respect tobarrier 11 and is likewise provided with apertures 31 and 32 adapated tobe in alignment under predetermined conditions with apertures 28 and 29.

As illustrated, the circuit breaker is in its closed position with themovable disconnecting contacts 26 and 27 extending through the alignedapertures in shutter 30 and barrier 11 to engage the respectivestationary contacts carried by the breaker. Since it is requisite thatthe main circuit breaker be open before the disconnecting contacts areopen, it is necessary to provide interlocking means between the mainswitch operating mechanism and the disconnecting mechanism. It is alsodesirable that after the disconnecting contacts are separated thereshall be an insulating barrier interposed between the stationary andmovable contacts. To accomplish these purposes there is provided meansfor raising contacts 26 and 27 through the apertures in the barrier andshutter into the compartment formed by partitions 10 and 11, hereinafterreferred to as the disconnecting switch compartment. The above operationis of course permitted only after opening of the main circuit breaker,thereby rendering the interlocking means ineffective. The operation ofraising the movable contacts 26 and 2'7 into the disconnecting switchcompartment also effects translational movement of shutter 30 so that ittakes the position illustrated in Fig. 3 wherein apertures 28 and 29 areclosed by the shutter thereby interposing an isolating and insulatingbarrier between the stationary and movable contacts of the disconnectingdevice.

The operating means to effect disconnection and isolation of the circuitbreaker in the manner above described comprises a hand wheel 33 orequivalent operating mechanism, disposed in the aforesaid operatingcompartment, having a worm connection with a toggle operating member 34arranged so that rotation of wheel 33 imparts longitudinal movement tomember 34. The shaft of wheel 33 has mounted thereon a notched disc,

35, for coacting with a pawl 36'pivoted at 36a, which in turn iscontrolled by the main switch operating mechanism. Pawl 36 is normallybiased by spring 37 in clockwise direction to engage one of the notchesof disc.35 and thereby restrain wheel 33 from rotative movement. Thelower arm of pawl 36 is connected to a rod 38 guided ,for reciprocalmovement and provided with a lug 39 depending through an aperture inbarrier 11 into the path of a pivoted latch actuator member 40 having adepending portion 41 likewise in the path of movement of a'pivotedmember 42 forming part of the circuit breaker Referring to Fig. 3, itwill be noted that when the main circuit breaker is tripped to openposition, link 42 in moving counter-clockwise engages the dependingportion 41 of latch actuator 40, moving the same in clockwise directionto engage lug 39 and release pawl 36 from engagement with disc 35.Accordingly, wheel 35 being free to rotate, it is moved in a directionto straighten the toggle 43 thereby raising lever 44, pivoted at 45, andsupporting at its free end, as by a link 46, 150

. connections with conductors 53 partment the entire the'protectivediaphragm, and the circuit breaker a pair of insulating supports 47. and48 upon which are respectively mounted the movable contacts 26 and 27 ofthe disconnecting device. Contacts 26 and 2'7 are electrically connectedthrough flexible braided conductors 49 and 50 to stationary insulatingsupports 51 and 52 providing terminal and 54 leading to apparatus in thesuperstructure as hereinafter described. I a

A bell crank member 55 having a fixed pivot 55a is connected at one endthrough a link 56 with themovable shutter 30. The opposite end of thebell crank is disposed in the path of a lug 5'7 carried by'bushings ,47and 48 and movable therewith. As illustrated in Fig. 3, rotation ofwheel 33 in the proper direction serves to straighten toggle 43 therebyrotating lever 44 in counter clockwise direction to separate contacts 26and 27 from their coacting contacts and to withdraw them upwardly intothe disconnecting switch compartment. As the movable contacts near thelimits of their upward movement, lug 57, comprising an element of alost-motion connection between the operating mechanism and the shutter,comes into engagement with the coacting arm of bell crank 55 to rotateit in clockwise direction and thereby move the insulating shutter 30towards, the left to close apertures 28 and 29. It will be apparent thatrotation of wheel 33 in the opposite direction, when not restrained bythe aforesaid interlocking means, permits the shutter 30 to move to theright, as under bias of a spring (not shown) to open apertures 28 and 29and to project the movable contacts downwardly into engagement with thecontacts 24 and 25.

In order that the operator may readily determine the position of thedisconnecting device, a visual indicator 58 is operatively connected inany suitable manner, as by linkages 59 with lever 44 whereby theposition of indicator 58 is indicative of the position of the movablecontacts.

When the main circuit breaker has been tripped open and thedisconnecting and isolating operations above described the circuitbreaker may be removed from its compartment. To this end, the door orpanel 8 is opened and a conventional truck 59, which may be of the typeusually employed in factories for moving about heavy objects is movedinto the cubicle and underneath the tray 13 upon which circuit breakeris mounted. After the truck has been elevated in a well known manner toraise the tray 13 slightly from the floor of the comunit comprising thetray,

and its operating mechanism are moved out of the cubicle withoutdisturbing any of the accessory equipment. The operator is thereforeable to effect the disconnecting operation at will independently of themovement of thecircuit breaker. In other words, the disconnectingoperation and withdrawal of the circuit breaker from the cubicle are notnecessarily concurrent as in the case where the movable contacts of thedisconnecting device are mounted on the circuit breaker itself.

The disconnecting switch compartment, whose lower portion comprisesbarrier 11, a vertically extending portion 60, and a removableinsulating barrier 61, houses the usual potential transformer 62 whosesecondary leads may be disposed. as at 63:

The upper part of the cubicle or superstructure comprises twocompartments, the compartment defined by the top section 6 and partition9 being have been completed,

designated as the transfer bus compartment, and the compartment definedby .partitions 9 and 10 being designated as the main bus compartment.The main bus compartment is divided into two sections" by a removableinsulating barrier 70, one

of which contains supporting members for the current transformer 64 towhich are mounted conductors 65 connecting the current transformerthrough partition 9 to a transfer switch 66. The primary lead cable 64aof the current.

transformer 64, extends through partition 10 along the rear wall of thecubicle within the passage 5a. As illustrated, the primary cable passesout through the bottom of the cubicle, but it is apparent that it mayextend, if desired, along the rear wall thereof through the top. Themain busses are designated at 69 in the front section of the main buscompartment, the circuit breaker in the present instance being of thethree phase type, as illustrated in Fig. 2 wherein three individual setsof contacts, such as 26 and 27 are simultaneously operated by theoperating wheel 33 I The transfer 66 within the transfer bus compartmentis isolated from the remainder of the compartment by a switch supportingpartition or wall 66a. Switch 66 may be operated either singly or ingang connection in any suitable manner as by a pivoted rod 67 operatedthrough a gearing 68 and crank 68a suitably disposed along the front ofthe cubicle.

The transfer busses 71 are mounted upon insulating supports in the usualmanner in the rear of the transfer bus compartment and are individuallyconnected to corresponding" contacts of the transfer switch.

It shall be understood that the current and potential transformerstogether with their disconnecting devices may be mounted uponthemmovable circuit breaker unit as in the case of certain types oftruck-type panels previously referred to. Furthermore, it is notessential that the movable contacts or the disconnecting device bevertically movable or that they shall partake only of rectilinearmovement. If desired, the movable disconnecting contacts may belaterally disposed with respect to the circuit breaker so that theypartake of horizontal movement; or they may be pivotally mounted, as inthe case of usual gang operated switches with the pivotal mountingsdisposed either on the circuit breaker unit or on the frame of thecubicle. In any event the disconnecting and isolating operation willtake place independently of movement of the circuit breaker. 1

With reference to Fig. 2 it will be noted that the cubicle takes up verylittle space and presents a comparatively compact appearance. This ismade possible without sacrificing any of the usual safety features byeliminating'the comparatively massive and eleborate mechanism foreffecting the disconnecting operation either by horizontal or verticalmovement of the breaker. Furthermore, due to the fact that no rear doorsare necessary, the cubicle may be disposed against a wall therebyincreasing the effective floor space of the station in which the cubicleis located. a

The protective diaphragm 21, together with the front section or door 8of the cubicle, form a double barrier tending to practically el minateoil throwfrom the cubicle in the event that the oil circuit breakerunder certain operating conditions violently ejects quantities of oiltherefrom. In prior constructions, wherein the front door or wall of thecell is relied upon to protect the operator exteriorly of cubicle, hotoil has been known to be projected through the spaces and cracks aroundthe door or wall to a considerable distance, injuring workmen about thestation. By providing a double barrier to form a dead space oil thrownfrom the circuit breaker is precluded from injuring an operator eventhough he may be standing close to the cubicle at the time of expulsionof oil from the breaker.

It shall be understood that changes in construction and arrangement ofthe apparatus within the cubicle may be made without departing from thespirit of my invention. For example, the superstructure of the cubiclemay be of the metal-clad type wherein the bus bars and accessoryequipment are immersed or embedded in suitable insulating material.Although the present arrangement whereby a single truck of inexpensiveconstruction may serve a plurality of cubicles to withdraw -the circuitbreaker therefrom when desired is preferable, due to the saving inmaterial and cost of construction, it is apparent that the circuitbreaker may be mounted upon its own truck in the usual manner, if sodesired.

The circuit connections for the'circuit breaker with respect to itsdisconnecting switches and main and transfer busses may be made in anysuitable manner which will afford suificient electrical protection andflexibility of operation, and by way of example, the single line diagramillustrated in Fig. 4 shows one way in which the system may beconnected. The oil circuit breaker '70, '71 and 72 are indicated asbeing within separate cubicles as defined by the dotted lines, theincoming line '73 being connected with breakers and 71, for optionalconnection to the main bus '74 or the transfer bus 75. The disconnectingswitches for breakers '70 and '71 are diagrammatically indicated at 76and '77 respectively. The circuit breaker 72 is interposed together withits disconnecting means 78, between the main bus and outgoing feeder 79.Feeder 79 may likewise be connected to the transfer bus through switch80.

For the purpose of enabling the oil circuit breaker to be tested andelectrically operated in a well known manner, a suitable secondarydisconnecting device or switch, not shown, may be employed.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. The combination with a cubicle compris-' compartment of a removablecircuit within said compartment, a protective wall section mounted onand carried by said unit forming, when the breaker unit is in operativeposition, the front wall of said compartment, and a movable instrumentpanel comprising a front wall of the cubicle and spaced from said wallsection whereby inspection of the rear of the instrument panel may behad without disturbing the breaker unit.

2. The combination with a cubicle comprising a circuit breakercompartment and a second compartment adjacent thereto, of a removablecircuit breaker unit disposed within said firstnamed compartment,disconnecting switching structure comprising a set of movablecontactmembers mounted within the second compartment, flexibleconductors connecting said movable contact members to fixed terminals insaid second compartment, the cooperating set of contact members beingmounted on the circuit ing a breaker unit mounted breaker, an insulatingshutter arranged to be interposed between said sets of contact members,and operating mechanism mounted within said second compartment forwithdrawing the movable contacts of the disconnecting switch entirelyinto the second compartment and interposing said insulating shutterbetween the stationary and movable contacts whereby complete electricalisolation of the circuit breaker is effected. i

3. Electrical switchgear comprising in combination a cubicle comprisinga plurality of compartments, a removable circuit breaker unit disposedin one of said compartments, disconnecting switching structure forisolating the circuit breaker disposed in another of said compartments,a protective diaphragm mounted on and carried by said removable unitforming a front wall of the circuit breaker compartment, said diaphragmbeing spaced from the front wall of the cubicle to form an operatingcompartment, an operating member for the disconnecting switchingstructure and operating means for the circuit breaker both disposed insaid last-named compartment, and a hinged front panel comprising a frontwall of the cubicle for permitting access to the aforesaid operatingcompartment.

4. Electrical switchgear comprising a housing having a plurality ofcompartments, a removable circuit breaker unit disposed in one of saidcompartments, bus bars and accessory equipment disposed in another ofsaid compartments, a disconnecting device for electrically isolating thecircuit breaker with respect to its bus bars and accessory equipmentcomprising stationary and movable contacts, the stationary contacts ofsaid device being mounted on and carried by the circuit breaker, apartition through which said movable contacts are withdrawn to theisolating position, a movable insulating shutter mounted on saidpartition adapted to be interposed between the movable and stationarycontacts, and mechanism operativeiy connected to said movable contactsand having a lost-motion connection with said shutter for effecting by asingle operation separation of said contacts and movement of theinsulating shutter therebetween.

5. Electrical switchgear comprising in combination a cubicle, a circuitbreaker unit mounted within the cubicle and spaced and separated by adiaphragm from the front wall of the cubicle, operating means for thecircuit breaker,- a disconnecting device for electrically isolating thecircuit breaker from other parts of the system in which it is connected,and an operating member for said disconnecting device, the operatingmember and operating means for the circuit breaker both being disposedin the space between the diaphragm and iront wall of the cubicle.

6. Electrical switchgear comprising in combination a cubicle, a hingedsection forming a front wall 0! the cubicle comprising an instrumentpanel, a removable circuit breaker unit disposed within the cubiclespaced and separated from said instrument panel whereby inspection ofthe rear of the panel may be had without change in position 01 thecircuit breaker unit, and supporting structure for the circuit breakerunit for permitting its withdrawal from the cubicle through the openingnormally closed by the instrument panel.

.7. Electrical switchgear comprising a cubicle having a plurality ofcompartments containing electrical equipment, a circuit breaker disposedin one of said compartments, structure for supporting said circuitbreaker in spaced relation with respect to the floor of its compartmentwhereby withdrawal of the circuit breaker from the cubicle may beeffected by auxiliary truck apparatus rolled beneath said breaker,disconnecting switching structure for electrically disconnecting andisolating the circuit breaker from other equipment inv the cubicle, andoperating mechanism carried by said cubicle for simultaneously openingthe contacts of the'disconnecting structure prior to withdrawal 0! thecircuit breaker from its compartment.

8. Electrical switchgear comprising in combination a cubicle comprisinga plurality of compartments separated by partitions of insulatingmaterial, a removable circuit breaker unit mounted on a tray on thefloor of the cubicle within one of said compartments, a protectivediaphragm mounted on and carried by said unit spaced from the front wallof the cubicle to form an operating compartment, disconnecting switchingstructure for isolating the circuit breaker disposed in a compartmentadjacent to and above the circuit breaker compartment, an operatingwheel for the disconnecting switch disposed together with operatingmeans for the circuit breaker in said operating compartment, andinterlocking means coacting with said operating wheel and operatingmeans whereby said wheel may be rotated to effect withdrawal of themovable contacts of the disconnecting switch from the stationarycontacts in the circuit breaker compartment only after the trippingoperation of the breaker.

9. Electrical switchgear comprising a cubicle having a circuit breakercompartment, a removable circuit breaker disposed within saidcompartment, a removable tray for supporting the breaker in spacedrelation to the floor of the compartment, and disconnecting switchingstructure for electrically disconnecting andisolatin'g the circuitbreaker from the system in which it is connected while the circuitbreaker is stationary within its compartment, said breaker adapted to beremoved laterally from the cubicle upon said tray after saiddisconnecting and isolating operation.

JAMES H. POWERS.

ias

